Improvement in grate-bars



' ,HENRY HARTWIG,

improvement in Etate Bar s.

No.- 122,460. Patemedjammsn.

X11136 I I lnv enizmr (i j W4 WW UNITED STATES PATENT Urrron.

HENRY HARTWIG, OF GOVINGTON, KENTUCKY.

IMPROVEMENT m GRATE-BARSQ Specification forming part of Letters Patent No. 122,460, dated January 2, 1872.

I, HENRY HARTW'IG, of Govington, Kenton county, State of Kentucky, have invented a certain new and useful Improvement in Grate- Bars, of which the following is a specification:

Nature and Objects of Invention.

My invention consists of a grate-bar composed of three or more bars cast in one piece in such a Way that all the bars are connected together laterally, and the central or intermediate ones are detached from the exterior bars longitudinally for the purpose of so locking the bars laterally as to prevent warping in that direction, and providing perfectly for the unequal longitudinal expansion and contraction.

Description of the Accompanying Drawing.

Figure 1 is afplan of my improved gratebar when composed or cast with three longitudinal bars. Fig. 2 is a longitudinal section of the same. Fig. 3 is a plan of my improved gratebar when cast with four longitudinal bars. Fig. 4 is a longitudinal section of the bar exhibited in Fig. 3. Fig. '5 is a cross-section of the bar shown in Figs. 3 and 4.

General Description.

of which is sufficiently separated from the others in the furnace to permit of shaking. The central or intermediate bar or bars D are connected to the outer bars A A by short curved bridges E, but they are free to expand or contract longitudinally independently ofthe side bars by reason of their having no connection with the end pieces B O. The curved character of .the bridges E assists in permitting the bar or bars D to expand or contract independently of the outer bars A A.

I do not desire to confine myself to the exact construction of the bar or bars D shown in the drawing, as the same result may be attained by making the bar D in two lengths,

separated at mid-length of the grate-bar, and I either disconnected from or attached to the end pieces B (3. So long as the bar D is not tied to both end pieces B O the effect is accomplished.

In order to give the bar great stiffness to resist the weight of the load in the furnace and yet provide for the introduction of cold currents of air to keep the bars so cold that clinkers cannot be formed upon them, I construct the outer bars A A of great depth and the intermediate ones of but little depth. This leaves a channel, F, throughout the entire length of the barrfor the passage of air.

Claim.

A grate-bar, composed of outer frame A A B O and intermediate bar or bars D, the latter being connected to frame AA by bridges 'E and disconnected from one or both of the ends B O, as and for the purpose specified.

In testimony of which inventionl hereunto set my hand.

HENRY HARTWIG. Witnesses HENRY MILLWARD,

J. L. WARTMANN. (149) 

